If lymphatic vessels are depressed in function or occluded by cancer treatment or the like, the lymph fluid does not flow smoothly. Consequently, the lymph fluid, which should normally be absorbed into the lymphatic vessels, may accumulate in spaces in the cellular tissues, resulting in swelling mainly in the arms and legs. Such swelling resulting from obstruction of the circulation of lymph fluid is known as lymphedema. Edema may also occur in the arms and legs owing to some disease in the blood vessels.
Manual lymphatic drainage is known as a method of treating such edema. The manual lymphatic drainage is effective in treating not only lymphedema but also vascular edema. With the manual lymphatic drainage, a body fluid such as lymph fluid accumulated in spaces in the cellular tissues is urged toward normally-functioning lymphatic vessels and blood vessels by massage performed with the human hands, thereby resolving the swelling. The manual lymphatic drainage needs to be performed almost daily, which is a heavy burden whether the patient oneself performs the massage or a nurse or the like massages the patient.
To lighten the load of carrying out manual lymphatic drainage, it is becoming common practice to perform lymphatic drainage using a pneumatic massage apparatus as an auxiliary of manual lymphatic drainage. A pneumatic massage apparatus used for this purpose has a plurality of air chambers disposed in series in a proximal direction from a distal position of an arm or a leg of a patient's body toward the center of the patient's body. Each air chamber is inflated with compressed air supplied thereinto to compress the patient's arm or leg by pneumatic pressure, thereby performing massage. Basically, a body fluid such as lymph fluid needs to be urged from the distal part of a patient's arm or leg toward the center of the patient's body. Therefore, usually, the air chambers are pressurized sequentially from a distal end air chamber located at the periphery side toward successively proximal air chambers to promote the flow of body fluid by the action of compressing the patient's arm or leg during pressurization (see Non-Patent Document 1).